Vitamine D en het risico op hart- en
vaatziekte*
Hier een inzicht van eigen ervaringen en bestudering van verschillende studies door de Amerikaanse cardioloog Dr. William Davis over
vitamine D.
Iedereen kent de risicofactoren voor het ontstaan van hart- en vaatzieke zoals hoog cholesterol, hoge bloeddruk, roken en diabetes. Doch veel van zijn patiënten hadden wel hart- en vaatproblemen doch geen van deze risicofactoren. Omdat de laatste jaren steeds meer onderzoek duidt op gevolgen van lage bloedwaarde vitamine D voor darm-, prostaat-, blaas en borstkanker, osteoporose (lage bloedwaarde vitamine D veroorzaken dat calcium minimaal wordt opgenomen), artritis, MS, ontstekingsziektes en ook meer en meer voor hoog cholesterol en tiglyceriden, hoge bloeddruk en hoge suikerwaarden was de cardioloog in de praktijk gestart met supplementen vitamine D als behandeling tegen hart- en vaatziektes met ongelofelijke resultaten. Het record was een 63% reductie van aderverkalking bij een vrouwelijke patiënt. Verschillende wetenschappelijke onderzoeken geven ook aan dat de ADH (aanbevolen dagelijkse hoeveelheid) voor vitamine D vele malen te laag is. 90% va de mensen heeft een te lage bloedwaarde vitamine D. Op zich is dat niet vreemd want bij het ouder wordt de mogelijkheid om zonlicht in het lichaam om te zetten in een actieve vorm van vitamine D wel tot 70% minder. Eigenlijk heeft bijna iedereen aanvulling met vitamine D nodig en dan een dagelijkse hoeveelheid die tot wel 10 keer hoger liggen dan de ADH !!! De ADH voor vitamine D is dus gewoon onjuist en zelfs voor de mens gevaarlijk.
Vitamin D: the newest coronary risk factor?
It's probably one of the most exciting health phenomena I've stumbled across in the last 10 years: I am absolutely, 100% convinced that deficiency of vitamin D is an enormously powerful risk for heart disease. What causes coronary heart disease? You'veheard the list-yawn-before: high cholesterol, high blood pressure, smoking, diabetes. Funny . . . Most of the people I know with heart disease have none of these factors. Clearly the list is incomplete. We already know that vitamin D deficiency is rampant, affecting as many as 90% of people in many regions of the U.S. Modern lifestyles guarantee it: Driving in cars, often in northern latitudes, and-shockingly-we wear clothes! Not to mention that aging alone guarantees a 70% or greater drop in our capacity to convert vitamin D to its active form in the skin. (I saw an 80-year old man just recently who sported deep, dark leathery tan from hours of sun every day. His blood level of active vitamin D: barely detectable.) The list of consequences of vitamin D deficiency is growing by the day: cancer of the colon, prostate, breast, and bladder; osteoporosis, arthritis, and fractures; multiple sclerosis; inflammatory diseases. But there's also lower HDL cholesterol, lower triglycerides, higher c-reactive protein (the measure of hidden inflammation), higher blood sugar, poor response to insulin, higher blood pressure-in other words, all factors that lead to heart disease. Does supplementation with vitamin D reduce your risk for heart disease? I think so. No-I absolutely am convinced it does. Over the last several years, I have actively worked to try and help patients reverse coronary heart disease. Not only have we succeeded, but we have succeeded on such an extraordinary scale that even I didn't believe it at first. In fact, our record holder for heart disease reversal has reduced her (yes, it's a woman) quantity of heart disease (atherosclerosis) by 63%. Yes, 63%. To my knowledge, this is unprecedented in the annals of modern medicine. We have a nation that is suffering extraordinary levels of severe and longstanding deficiency of this crucial nutrient. Why? Part of the answer is lifestyle. Another factor is the misguided advice originally drafted by the Food and Nutrition Board way back in the 1960s that has been upheld until now.
Vitamin D expert, Dr. Reinhold Vieth, at the University of Toronto has unequivocally stated: "The basis for adult vitamin D recommendations [was] arbitrary. Thirty-six years ago, an expert committee on vitamin D could provide only anecdotal support for what it referred to as ‘the hypothesis of a small requirement' for vitamin D in adults and it recommended one-half the infant dose, just to ensure that adults obtain some from the diet."
Imagine the same situation had developed with vitamin C: We'd all be toothless, arthritic, and ridden with open sores. We'd all be scratching our heads over something readily remedied by 30 mg of vitamin C. The same, I believe, has happened with vitamin D. We were misled by the limited understanding of this crucial nutrient, followed by the advice drafted in a vacuum of scientific experience, and were advised that vitamin D doses like 200-400 units were sufficient for adults. We then went on to have our high blood pressure, high blood sugars, diabetes, osteoporosis, and heart attacks.
Dr. Robert Heaney and colleagues at Creighton University determined that healthy males required 3000-5000 units of vitamin D per day just to maintain a stable vitamin D blood level. That's 10-fold-1000%-more than the previous Recommended Daily Allowance.
You thought your calcium supplement was helpful? When vitamin D is replenished to normal levels, intestinal calcium absorption quadruples. The notion that vitamin D intake of 200-400 units per day is adequate is not just untrue, it's dangerous to your health. We live in an enlightened age, one blessed with near-immediate dissemination of new information through information portals like HealthCentral. Don't subscribe to the advice of the 1960s on vitamin D any more than you'd insert a cassette into your 8-track tape player or scrawl anti-Viet Nam War graffiti on your neighborhood walls.
Out-of-the-box free-thinker and California psychiatrist, Dr. John Cannell, founder of the Vitamin D Council, was the first to bring the neglected vitamin D issue to my attention. He has stated:
Personally, I take 5,000 units in the late fall, winter, and early spring, and then I vary doses the rest of the time depending on sun exposure. I also have my 25(OH)D level checked twice a year, once in the early spring and again in the early fall. My 10 year-old daughter takes 2,000 units a day in the winter months and my three-year-old takes 1,000 units a day in the winter.
In a future post, we'll discuss how to go about deciding whether you need vitamin D (you do) and how to determine the quantity necessary for health.
Note:
The recommended Adequate Intake for vitamin D (by the Institute of Medicine of the National Academy of Sciences) is between 200-400 units per day. There are few dietary sources of vitamin D. An 8 oz glass of milk contains 100 units (though not always-inconsistency reigns). Other dairy products, like cheese and yogurt, tend to have little or no vitamin D added. Oily fish like salmon, mackerel, and sardines contain 200-360 units vitamin D per 3 ½ ounce serving. Many breakfast cereals contain 40-100 units per serving.
Despite this, more than 50% of people fail to obtain even the modest "Adequate" Intake every day.
For the scientifically-minded, here's a list of some important references on vitamin D:
References:
Grimes DS, Hindle E, Dyer T. Sunlight, cholesterol and coronary heart disease. QJ Med 1996;89:579-589.
Heaney RP, Davies KM, Chen TC, Holick MF, Barger-Lux MJ. Human serum 25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol;. Am J Clin Nutr 2003;77:204-210.
Holick MF. High prevalence of vitamin D inadequacy and implications for health. Mayo Clin Proc 2006 March;81(3):353-373.
Levis S, Gomez A, Jimenez C et al. Vitamin d deficiency and seasonal variation in an adult South Florida population. J Clin Endocrinol Metab 2005 Mar;90(3):1557-1562.
Lind L, Hanni A, Lithell H et al. Vitamin D is related to blood pressure and other cardiovascular risk factors in middle-aged men. Am J Hypertens 1995 Sep;8(9):894-901.
Vieth R. Vitamin D supplementation, 25-hydroyvitamin D concentrations, and safety. Am J Clin Nutr 1999;69:842-856.
Webb AR, Kline L, Holick MF. Influence of season and latitude on the cutaneous synthesis of vitamin D3: exposure to winter sunlight in Boston and Edmonton will not promote vitamin D3 synthesis in human skin. J Clin Endocrinol Metab 1988;67:373-378.
Zadshir A, Tareen N, Pan D, Norris K, Martins D. The prevalence of hypovitaminosis D among US adults: data from the NHANES III. Ethn Dis 2005 Autumn;15(4 Suppl 5):S5-97-101.
Zittermann A. Vitamin D and disease prevention with special reference to cardiovascular disease. Prog Biophys Mol Biol 2006 Sep;92(1):39-48.
Zittermann A. Vitamin D in preventive medicine: are we ignoring the evidence? Br J Nutr 2003
May;89(5):552-572.
(Oktober 2007)
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